Articular cartilage has limited capacity for natural regeneration and repair. In the present study, we evaluated kartogenin (KGN), a bioactive small heterocyclic molecule, for its effect on in vitro proliferation and chondrogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBMSCs) in monolayer culture and in co-culture models in vitro. OA osteochondral cylinders and hBMSCs were collected during total knee replacement. The effect of KGN on hBMSCs during 21 days of culture was monitored by real-time proliferation assay, immunofluorescence staining, histological assay, scanning electron microscopy (SEM) (imaging and multiplex enzyme-linked immunosorbent assay) ELISA assay. The rate of proliferation of hBMSCs was significantly increased by treatment with 10 µM KGN during nine days of culture. Histological and SEM analyses showed the ability of hBMSCs in the presence of KGN to colonize the surface of OA cartilage and to produce glycosaminoglycans and proteoglycans after 21 days of co-culture. KGN treated hBMSCs secreted higher concentrations of TIMPs and the secretion of pro-inflammatory molecules (MMP 13, TNF-α) were significantly suppressed in comparison with control without hBMSCs. Our preliminary results support the concept that 10 µM KGN enhances proliferation and chondrogenic differentiation of hBMSCs and suggest that KGN is a potential promoter for cell-based therapeutic application for cartilage regeneration.

This study aims to analyze the effect of intravenous administration of tranexamic acid (TA) on reducing the risk of revision for acute and delayed periprosthetic joint infection (PJI) after primary total knee replacement (TKR). This prospective observational cohort study included 1,529 TKRs (396 males, 1,133 females; mean age 67.8 years; range, 44 to 85.1 years) performed between January 2003 and October 2017. We analyzed the revision rate for acute and delayed PJI in a group of 787 TKRs with preoperatively intravenously administered TA (TA group) in comparison with a group of 742 TKRs without administration of TA (non-TA group). Multiple logistic regression analysis was used to evaluate significant predictors of TKR revision for acute and delayed PJI. Revision surgery due to PJI was recorded in one patient in the TA group and eight patients in the non-TA group. Cumulative revision rate of TKR was significantly lower in the TA group (0.13% vs. 1.08%, hazard ratio 0.113; 95% confidence interval [CI] 0.0147-0.937; p=0.043). Multivariate logistic regression analysis confirmed two predictors of revision: being aged over 75 years at the time of primary surgery (odds ratio [OR] 8.464; 95% CI: 2.016-35.54; p=0.004) and male gender (OR: 7.9; 95% CI: 1.879-33.26; p=0.005). The use of TA was shown as the significant protective factor (OR: 0.109; 95% CI: 0.0128-0.929; p=0.043). We have found a lower cumulative revision rate of TKR for acute and delayed PJI when TA was used. We think that the preoperative intravenous use of TA may be an effective, safe and inexpensive method for the prevention of PJI.

Background: The aim of this study is to determine the effect of three doses of intra-articular injection of platelet-rich plasma (PRP) into the osteoarthritic (OA) knee joint on the functional status and on the changes in the levels of specific OA biomarkers in blood serum. Methods: Forty patients with unilateral primary knee osteoarthritis were enrolled in this single center, prospective clinical trial. For each patient, three intra-articular PRP injections were administered one week apart. Clinical and laboratory assessment was performed before the first PRP injection (baseline), and 3 months after the third PRP application (3-month follow up). Pain in the affected knee joint was assessed with the Visual Analog Scale for Pain (VAS). Change in clinical status was evaluated with the Western Ontario and McMaster Universities Arthritis Index Questionnaire (WOMAC). Concentrations of 19 biomarkers (EGF, Eotaxin, FGF-2, GRO, IL-10, IL-1RA, IL-8, IP-10, MCP-1, PDGF-AB/BB, RANTES, MMP-3, MMP-13, Collagen type 2, BMP-2, TIMP-1, TIMP-2, TGF beta 1, and COMP) in the serum of studied patients were quantified. Results: At 3-month follow up, there was a significant decrease in the VAS score and significant improvement in the WOMAC score. There was a significant decrease in the levels of Eotaxin, MCP-1, MMP-1, IL-10, EGF, PDGF-AB/BB, TGF- β1 compared to baseline levels. A significant increase in markers BMP-2, COMP, Collagen type 2 and GRO was found at the same time point. There was no significant change in the concentrations of other biomarkers (FGF-2, IL-1RA, IL-8, IL-10, MMP-3, RANTES, TIMP-1, TIMP-3). Conclusions: We found an increase in specific pro-anabolic and anti-inflammatory biomarkers with a concomitant decrease in pro-inflammatory biomarkers at 3 months after three intra-articular applications of PRP. Significant improvement in VAS and WOMAC scores was observed. Treatment with PRP may be an effective therapeutic option with anti-inflammatory and regenerative potential in patients with primary knee OA.

This study aims to compare the efficacy and safety of intra-articular tranexamic acid (TA) versus intravenous (IV) TA in the reduction of perioperative blood loss and the degree of early postoperative complications associated with primary unilateral cemented total knee replacement. This prospective randomized study included 90 patients (36 males, 54 females; mean age 68.7 years; range 47 to 82 years) with knee osteoarthritis undergoing a unilateral cemented total knee replacement. Patients were randomized into three groups: group 1 received TA intravenously (dose 10 mg/kg) 20 minutes preoperatively and three hours after first dose, group 2 received TA (dose 3 g) locally (intra-articular) into surgical site, and group 3 did not receive TA. We measured perioperative blood loss, volume of drained blood in 24 hours postoperatively, overall blood loss, decrease in hemoglobin and hematocrit levels, and amount of blood transfusion. There were no differences between the groups in terms of patient preoperative demographics. Local or IV administration of TA significantly reduced the number of blood transfusions and blood losses in drainage. Intravenous application of TA was associated with statistically significantly higher hemoglobin and hematocrit levels and lower overall postoperative blood losses. No serious complications were observed in any of the groups. Intra-articular TA was equally effective as IV regimen in reducing the number of blood transfusions. However, IV administration of TA was associated with overall lower blood loss. Our results showed that IV administration of TA during total knee replacement is superior compared to intra-articular administration of TA.

There is a lack of in vitro models able to plausibly represent the inflammation microenvironment of knee osteoarthritis (OA). We analyzed the molecules released from OA tissues (synovial membrane, cartilage, infrapatellar fat pad) and investigated whether the stimulation of human synovial fibroblasts (SFs), with synthetic cytokines (IL-1β and TNF-α or IFN-γ) or conditioned media (CM) from OA tissues, influence the SFs’ response, in the sense of pro-inflammatory cytokines, chemokines, growth factors, and degradative enzymes modulation. Human SFs were obtained from OA synovial membranes. SFs and their CM were analyzed for biomarkers, proliferation rate, protein profile and gene expression, before and after stimulation. Real-time PCR and multiplex assays quantified OA-related gene expression and biomolecule production. Unlike other activators, CM from OA synovial membrane (CM-SM), significantly up-regulated all genes of interest (IL-6, IL-8, MMP-1, MMP-3, RANTES, MCP-1, TSG-6, YKL-40) in SFs. Multiplex immunoassay analysis showed that levels of OA-related cytokines (IL-6, IL-8, MCP 1, IL-1Ra), chemokine (RANTES) and growth factor (VEGF), produced by CM-SM stimulated SFs, increased significantly compared to non-stimulated SFs. Molecules released from the SM from OA patients induces OA-like changes in vitro, in specific OA synovial populations (SFs). These findings promote the use and establish a compelling in vitro model that simulates the versatility and complexity of the OA disease. This model, in the future, will allow us to study new cell therapies or test drugs by reducing or avoiding animal models.

Aim of the study. To investigate the relationship between serum lipoprotein (a) [Lp(a)] concentration and the risk of ischaemic stroke (IS) and its subtypes. Clinical rationale for the study. Lp(a) plays a role in atherogenic, pro-thrombotic, and antifibrinolytic processes. Elevated plasma Lp(a) is a strong independent risk factor for the development and progression of atherosclerotic disease. The association between lipoproteins and IS is more complex than that reported for cardiovascular diseases, with inconsistent and contradictory results from epidemiological studies. Material and methods. 231 patients with acute IS (defined as cases) and 163 age- and sex-matched control subjects were included in this prospective case-control study. Demographic and clinical variables (i.e. age, sex, smoking, presence of chronic diseases and concomitant medication) and laboratory data (i.e. concentrations of total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, triglycerides, Lp(a), apolipoprotein A1, apolipoprotein B) were recorded. Results. The mean age and the percentage of men did not significantly differ between groups. Compared to controls, there was a significantly higher percentage of cases reported with concomitant diseases: diabetes mellitus, myocardial infarction, ischaemic heart disease, peripheral arterial disease, and atrial fibrillation. The study showed a significantly higher serum Lp(a) concentration in cases than in control subjects (81.81 nmol/L [c.32.7 mg/dL] vs. 59.75 nmol/L [c.23.9 mg/dL]; p = 0.036) and found an association between Lp(a) levels stratified by quartiles and the risk for ischaemic stroke (Q1 [Lp(a) < 13 nmol/L] vs. Q4 [Lp(a) > 117 nmol/L]: OR 2.23; 95% CI 1.23-4.03; p = 0.008). A subgroup analysis based on the TOAST classification of IS also showed a significant association between Lp(a) value of more than 75 nmol/L (30 mg/dL) and the risk of large-artery atherosclerosis stroke compared to the controls (OR 2.4; 95% CI 1.39-3.93; p = 0.001), as well as a statistically non-significant association with other subtypes of IS. The influence of Lp(a) remained significant even after adjusting for established risk factors for IS (OR 1.99; 95% CI 1.05-3.76; p = 0.04; respectively for the large-artery atherosclerotic subtype: OR 2.54; 95% CI 1.39-4.67; p = 0.003). Conclusion. We found that Lp(a) is an independent risk factor for ischaemic stroke, and for the large-artery atherosclerotic subtype of ischaemic stroke. Keywords: ischaemic stroke subtypes lipoprotein (a) risk factor